ISO 20391-1:2026

Biotechnology — Cell counting — Part 1: General requirements and recommendations for cell counting analytical methods ISO 20391-1:2026

Publication date:   Jul 28, 2026

Scope

This document provides standard terminology related to cell counting for biotechnology. This document describes counting of cells in suspension (generally cell concentration) and cells adhered to a substrate (generally area density of cells). This document provides key considerations for general counting methods (including total and differential counting, and direct and indirect counting) as well as for fit for purpose method selection, sources of variability in the measurement process, and data analysis and reporting.
This document is applicable to the counting of all cell types – mammalian and non-mammalian (e.g. bacteria, yeast) cells.
NOTE            Several sector or application-specific international and national standards for cell counting currently exist. When applicable, the user can consult existing standards when operating within their scope (e.g. specific measurement techniques or applications).